Submission #143778

#	Time	Username	Problem	Language	Result	Execution time	Memory
143778		jwvg0425	Arranging Shoes (IOI19_shoes)	C++17	100 / 100	219 ms	24488 KiB

shoes

#include "shoes.h"
#include <vector>
#include <queue>
#include <algorithm>
#include <iostream>
#include <string>
#include <bitset>
#include <map>
#include <set>
#include <tuple>
#include <string.h>
#include <random>
#include <functional>
#include <assert.h>
#include <math.h>
#define all(x) (x).begin(), (x).end()
#define xx first
#define yy second

using namespace std;

using i64 = long long int;
using ii = pair<int, int>;
using ii64 = pair<i64, i64>;

constexpr int clog2(int n) { return ((n < 2) ? 1 : 1 + clog2(n / 2)); }

template<typename T, typename Merge>
class SegmentTree
{
public:
    SegmentTree(Merge m)
        :merge(m) {}

    void init(vector<T>& raw_)
    {
        raw = raw_;
        n = (int)raw.size();
        int sz = (1 << (clog2(n) + 1));
        data.resize(sz);

        _init(raw, 1, 0, n - 1);
    }

    T modify(int idx, function<T(T)> modifier) { return update(idx, modifier(raw[idx])); }
    T update(int idx, const T& newVal) { raw[idx] = newVal; return _update(1, 0, n - 1, idx, newVal); }
    T query(int left, int right) { return _query(1, 0, n - 1, left, right); }

private:
    vector<T> raw;
    vector<T> data;
    int n;
    Merge merge;

    T _init(vector<T>& raw, int node, int start, int end)
    {
        int mid = (start + end) / 2;
        if (start == end)
            return data[node] = raw[start];
        else
            return data[node] = merge(_init(raw, node * 2, start, mid),
                _init(raw, node * 2 + 1, mid + 1, end));
    }

    T _update(int node, int start, int end, int index, const T& newVal)
    {
        if (index < start || index > end)
            return data[node];

        if (start == end)
            data[node] = newVal;
        else
        {
            int mid = (start + end) / 2;
            data[node] = merge(_update(node * 2, start, mid, index, newVal),
                _update(node * 2 + 1, mid + 1, end, index, newVal));
        }

        return data[node];
    }

    T _query(int node, int start, int end, int left, int right)
    {
        if (left <= start && end <= right)
            return data[node];

        int mid = (start + end) / 2;

        if (mid < left)
            return _query(node * 2 + 1, mid + 1, end, left, right);

        if (mid + 1 > right)
            return _query(node * 2, start, mid, left, right);

        return merge(_query(node * 2, start, mid, left, right),
            _query(node * 2 + 1, mid + 1, end, left, right));
    }
};

template<typename T, typename Merge>
SegmentTree<T, Merge> segTree(Merge merge)
{
    return SegmentTree<T, Merge>(merge);
}

set<int> mi[100005];
set<int> pl[100005];

long long count_swaps(vector<int> s) {
    vector<bool> used(s.size(), false);

    long long ans = 0;
    vector<int> raw(s.size(), 1);

    auto tree = segTree<int>([](const int& l, const int& r) { return l + r; });
    tree.init(raw);

    for (int i = 0; i < s.size(); i++)
    {
        if (s[i] > 0)
            pl[s[i]].insert(i);
        else
            mi[-s[i]].insert(i);
    }

    for (int i = 0; i < s.size(); i++)
    {
        if (used[i])
            continue;

        if (s[i] > 0)
        {
            int near = *mi[s[i]].lower_bound(i);
            mi[s[i]].erase(near);
            used[near] = true;
            ans += tree.query(0, near) - tree.query(0, i);
            tree.update(near, 0);
        }
        else
        {
            int near = *pl[-s[i]].lower_bound(i);
            pl[-s[i]].erase(near);
            used[near] = true;
            ans += tree.query(0, near) - tree.query(0, i) - 1;
            tree.update(near, 0);
        }
    }

    return ans;
}

Compilation message (stderr)

shoes.cpp: In function 'long long int count_swaps(std::vector<int>)':
shoes.cpp:118:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i = 0; i < s.size(); i++)
                     ~~^~~~~~~~~~
shoes.cpp:126:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i = 0; i < s.size(); i++)
                     ~~^~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 20 / 20
• Subtask 3: 20 / 20
• Subtask 4: 15 / 15
• Subtask 5: 20 / 20
• Subtask 6: 15 / 15